Review reviewHigh

CVE-2025-40012

Linux

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix warning in smc_rx_splice() when calling get_page() smc_lo_register_dmb() allocates DMB buffers with kzalloc(), which are later passed to get_page() in smc_rx_splice(). Since kmalloc memory is not page-backed, this triggers WARN_ON_ONCE() in get_page() and prevents holding a refcount on the buffer. This can lead to use-after-free if the memory is released before splice_to_pipe() completes. Use folio_alloc() instead, ensuring DMBs are page-backed and safe for get_page(). WARNING: CPU: 18 PID: 12152 at ./include/l...

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2025.10.21
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix warning in smc_rx_splice() when calling get_page() smc_lo_register_dmb() allocates DMB buffers with kzalloc(), which are later passed to get_page() in smc_rx_splice(). Since kmalloc memory is not page-backed, this triggers WARN_ON_ONCE() in get_page() and prevents holding a refcount on the buffer. This can lead to use-after-free if the memory is released before splice_to_pipe() completes. Use folio_alloc() instead, ensuring DMBs are page-backed and safe for get_page(). WARNING: CPU: 18 PID: 12152 at ./include/l...

Affected product and versions

Product
Linux
Affected versions
>= f7a22071dbf316c982fb44308874bd7ad9ac2091 < 14fc4fdae42e34d7ee871b292ac2ecc61c2c5de7, >= f7a22071dbf316c982fb44308874bd7ad9ac2091 < d5411685dc2f6ac7bdf01a0a204d56cae38c6cf6, >= f7a22071dbf316c982fb44308874bd7ad9ac2091 < a35c04de2565db191726b5741e6b66a35002c652, >= 6.10
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available